Electric steam boiler



April 26, 1949. C. AS1-EEN 2,468,244

'ELECTRIC STEAM BOILER Filed Jun 2, 1945 ffffm M7 Patented Apr. 26, 1949 ELECTRIC STEAM BOILER Carl August Steen, Getinge, Sweden Application June 2, 1945, Serial No. 597,320 In Sweden December 14, 1942 Claims. 1

The present invention relates to an electric steam boiler having electrodes in direct contact with the water to be evaporated. Boilers of this type having usually been provided with iixed electrodes, and the electric power has thereby been regulated by varying the water level by means of pumps in order to cause only a part of the electrodes, corresponding to the effect desired, to remain in contact with the water. This regulating means, however, is complicated and expensive.

The object of my invention is to provide an automatically regulated boiler of a simple construction without the use of any regulating pumps.

The invention is illustrated by way of example in the accompanying drawing, showing an electric steam boiler in a vertical section.

The boiler comprises a lower main casing I and an upper cap 2 which by means of rings 3 and 4 and an intermediate packing washer are pressed tightly against each other by bolts 5. The electrodes I5 are located side by side and have substantially vertical contact surfaces, between Which the current passes in substantially horizontal direction, and they are supported by insulators 8 mounted on a plate I. The insulators are'connected with inlets ID by means of helical conductors 9 allowing a vertical motion of the electrodes. A plate 'I supporting the electrodes is united to a rod II passing through a stuing box I2 provided with a tightening packing and welded on a plate I3 which is welded together with the upper boiler portion 2 and a cylindrical drum I4. The rod II rests by means of a ring I5 against the plate I3, as the electrode system occupies its undermost position, and to prevent the system from turning round the rod is provided with a fork shaped member I6 embracing-a iixed guide I'I.

The electrode system is loaded by a number of weights I8 resting on the ring I5. In its upper positions the rod II presses against a plate I9 at the end of a helical spring '20 which is fastened to a screw spindle 2| with a hand wheel 22. The screw spindle 2l is `provided with a nut 23 fixed on a yoke 24 which extends over the drum I4 and is fastened thereto by means of bolts.

The surface of the -water in the boiler is maintained at a constant level by a illoat valve 25 connected at 26 to a feed water pipe. 2'I is a gauge glass, 28 a steam outlet and 29 a return pipe for condensation Water.

The boiler is started by switching in the circuit, and as the boiler pressure reaches a certain value the electrode system is raised by a force corresponding to the steam pressure and the sectional area of the rod II in the guide I2. As part of the electrode surface is brought out of Contact with the water, the steam generating effect is reduced, and for a constant steam consumption the electrode system will be automatically adjusted at a level, where the electric power generates steam of a pressure corresponding to the weight of the electrode system. If the steam consumption changes, the contact surface will vary correspondingly in order to maintain a constant steam pressure.

By means of the three loading weights I8 the steam pressure may be increased in three steps, For obtaining intermediate values it is possible to use a series of additional weights or the additional pressuure from the spring 20. This spring should thereby have a sufficient length to allow the electrode system to be adjusted into such a high position that the electric eiect corresponds only to the heat losses of the boiler. It is obvious, however, that the electrode system may be loaded also in different other ways.. Thus it is l possible to use a lever arm to be loaded beside the boiler or a water tank to be filled and emptied by a rubber tube. The drum I4 may be provided with a pipe 30 for draining off condensation water.

At the top of the boiler is provided an exhaust pipe 3l for air and oxyhydrogen gas with a twoway cock 32 having in one end position a great and in the other end position a very narrow discharge area. When starting the boiler the cock is quite open so that the air might escape at beginning steam generation. Thereafter the cock is to be shifted into its other position, so that under normal operation of the boiler the oxyhydrogen gas, which is lighter than the steam and therefore will be collected under the cap 2, might continuously be blown out together with only such a small quantity of steam which is of no practical importance. A limited leakage in the guide I2 may also serve the same purpose.

What I claim is:

l. In an electric steam boiler, the combination of a valve for maintainnig a constant water level in the boiler with electrodes in contact with the water, said electrodes being located side by side and having substantially vertical contact surfaces, between which the current passes in substantially horizontal directions, a rod supporting said electrodes, a stufng box in the top portion of the boiler, said rod passing through said stuffing box slidably with a sectional area corresponding to the weight of the slidable rod system divided by the steam pressure and thus constituting steam pressure responsive means for automatically adjusting the position of the electrodes relative to the water to maintain a constant steam pressure, a limit stop on said rod for the lowest position of the electrodes, and means for loading the projecting upper end of said rod.

2. In an electric steam boiler, the combination of a float valve for maintaining a constant water level in the boiler with electrodes in contact with the water, said electrodes being located side by side and having substantially vertical contact surfaces, between which the current passes in substantially horizontal directions, a rod supporting said electrodes, a stuing box in the top portion of the boiler, said rod passing through said stuihng box slidably with a. sectional area corresponding to the weight of the slidable rod system divided by the steam pressure and thus constituting steam pressure responsive means for automatically adjusting the position of the electrodes relative to the water to maintain a constant steam pressure, a limit stop on said rod above said stuing box for the lowest position of the electrodes, and a loading weight adapted to rest on the projecting end of said rod.

3. In an electric steam boiler, the combination of a iioat valve for maintaining a constant water level in the boiler With electrodes in contact with the water, said electrodes being located side by side and having substantially vertical contact surfaces, between which the current passes in substantially horizontal directions, a rod supporting said electrodes, a stuffing box in the top portion of the boiler, said rod passing through said stuffing box slidably with a sectional area corresponding to the weight of the slidable rod system divided by the steam pressure land thus constituting steam pressure responsive means for automatically adjusting the position of the electrodes relative to the water to maintain a constant steam pressure, a limit stop on said rod above said stuffing box for the lowest position of the electrodes, and a resilient member forming a limit stop for the highest position of the electrodes.

4. In an electric steam boiler, the combination of a float valve for maintaining a constant water level in the boiler with electrodes in contactwith the water, said electrodes being located side by side and having substantially vertical contact surfaces, between which the current passes in 4 substantially horizontal directions, a rod supporting said electrodes, a stulng box in the top -portion of the boiler, said rod passing through said stuing box slidably with a sectional area corresponding to the weight of the slidable rod system divided by the steam pressure and thus constituting steam pressure responsive means for automatically adjusting the position of the electrodes relative to the water to maintain a, constant steam pressure, means for loading the projecting upper end of said rod, and a small leakage passage at the top of the boiler for continuously exhausting oxyhydrogen gas from the boiler,

5. In an electric steam boiler, the combination of a iioat valve for maintaining a constant water level in the boiler with electrodes in contact with the water, said electrodes being located side by side and having substantially vertical contact surfaces, between which the current passes in substantially horizontal directions, a rod supporting said electrodes, a stuffing box in the top portion of the boiler, said rod passing through said -stufling box slidably with a sectional area corresponding to the weight of the slidable rod system ,divided by the steam pressure and thus constituting steam pressure responsive means for automatically adjusting the position of the electrodes relative to lthe .water to maintain a constant steam pressure, a drum extending upwards from said top portion and enclosing the projecting end of said rod, weights for loading said projecting end, a spring buffer carried by said drum and located in the prolongation ofthe rod, and means for continuously exhausting oxyhyrogen gas iromthe boiler.

CARL AUGUST STEEN.

REFERENCES CITED The following references are of record in the file of this patent:

UNTTED STATES PATENTS Number Name Date 1,424,340 Cavitt i Aug. 1, 1922 1,646,746 Carroll Oct. 25, 1927 1,680,397 yStransky Aug. 14, 1928 1,706,146 Davidsen Mar- 19, 1929 1,714,578 Weiss May 28, 1929 1,941,020 Poindexter Dec. 26, 1933 2,024,467 Mason Dec. 17, 1935 A2,387,103 Wicks Oct. 16, 1945 

